Question: Solve for $x$ and $y$ using substitution. ${4x-6y = -6}$ ${y = x-1}$
Solution: Since $y$ has already been solved for, substitute $x-1$ for $y$ in the first equation. ${4x - 6}{(x-1)}{= -6}$ Simplify and solve for $x$ $4x-6x + 6 = -6$ $-2x+6 = -6$ $-2x+6{-6} = -6{-6}$ $-2x = -12$ $\dfrac{-2x}{{-2}} = \dfrac{-12}{{-2}}$ ${x = 6}$ Now that you know ${x = 6}$ , plug it back into $\thinspace {y = x-1}\thinspace$ to find $y$ ${y = }{(6)}{ - 1}$ $y = 5$ You can also plug ${x = 6}$ into $\thinspace {4x-6y = -6}\thinspace$ and get the same answer for $y$ : ${4}{(6)}{ - 6y = -6}$ ${y = 5}$